Putin has faced calls inside Russia from some hardliners to change Russia's nuclear doctrine, which sets out the conditions under which Russia would use a nuclear weapon, though Putin said last year he saw no need for change.

Broadly, the doctrine says such a weapon would be used in response to an attack using nuclear or other weapons of mass destruction, or the use of conventional weapons against Russia "when the very existence of the state is put under threat".


Is a tactical nuclear strike against a military target different on a legal standpoint than a tactical nuclear strike against a civilian target, or does international law doesn't make a difference between the two when it comes to the level of severity in terms of war crime? I was wondering about this, because it seems Russia thinks they're different and thus are or at least pretend to be seriously considering using them against military targets.

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    This doctrine is most notable for undermining concerns that Russia would first strike with nuclear weapons over outside intervention in the Ukraine War which it threatened to do earlier in that war.
    – ohwilleke
    Commented May 10 at 18:44
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    Legal rules don't apply to nuclear powers with a sufficient number of nukes (so, China, US and Russia) because no one is capable of enforcing the law on them without starting WWIII. Game theory would be a better framework for this question. Commented May 10 at 23:46
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    That word doesn't mean what you think it means. Which is important for legal questions. A nuclear strike against a civilian target is not tactical, it's strategic or a mistake, even if it uses small weapons designed for tactical purposes.
    – david
    Commented May 11 at 22:14

4 Answers 4


They are definitely different. Deliberately striking a civilian target, with any kind of weapon, is always a war crime. Striking a military target is not, unless some other rules are broken.
As for striking military targets with nuclear weapons:

The primary rules under jus in bello are found in the law of armed conflict, which today is widely termed international humanitarian law (IHL). Under IHL, while states ‘do not have unlimited freedom of choice of means in the weapons they use’, there is no requirement that each weapon be specifically ‘authorized’ for its use to be lawful; use of any given weapon will only be unlawful when, and to the extent that, it is prohibited by an applicable conventional or customary rule

So nuclear weapons are not blanket forbidden. But using them may break:

  1. The rule of distinction

The rule of distinction in attacks is a norm of customary international law, applicable in non-international armed conflicts as it is in international armed conflicts. Accordingly, any weapon that is incapable of distinguishing between civilians/civilian objects and military targets is considered inherently indiscriminate and its use is always unlawful.

I'm not an expert in nuclear weapons so I don't know if they are capable of hitting e.g. a military base without scorching all villages around it.

  1. The rule of proportionality

A supporting rule, that of proportionality in attacks, holds that even if an attack is effectively directed against military objectives, civilian harm (deaths, injuries, damage to civilian objects, or a combination thereof) it must not be launched if it may be expected to be excessive when compared with the direct and concrete military advantage anticipated. Arguably, environmental damage must also be assessed as part of the proportionality rule.

  1. The unnecessary suffering rule

A second oft-cited scenario concerns use of a nuclear weapon to destroy an enemy army situated in a desert. Judge Schwebel concluded, justly, that in ‘certain circumstances, such a use of nuclear weapons might meet the tests of discrimination and proportionality; in others not.’ But this scenario also evokes another general rule of IHL, namely the prohibition of the use of means and methods of warfare of a nature to cause superfluous injury or unnecessary suffering (the unnecessary suffering rule). This prohibition is one of the very scarce IHL rules designed to protect combatants while they are participating directly in hostilities.

Quotations came from Nuclear Weapons Under International Law: An Overview October 2014

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    Good answer, but deliberately striking a civilian target can be allowed under the law of war. Examples: collateral damages (command post under a hospital, striking the hospital and knowingly killing non-combattants inside), strategic targets (striking a well giving water to enemies, a power plant or a civilian arms factory), civilian combattants (partisans, mercenaries).
    – Yves
    Commented May 10 at 8:11
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    @Yves Maybe I should write "targeting". In your examples there is a military target that is to be struck, and a civilian facility that receives collateral damage. I mean a situation when a strike has no military target to destroy - it is aimed at civilians. Commented May 10 at 8:52
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    @Yves No. Attacking hospitals is off limits. And putting valid military targets (wounded soldiers are not valid targets) into the proximity of a hospital then that itself would be a war crime as it endangers civilians. Some collateral damage is permissible if the target is primarily military. Targeting energy supply is hotly debated, water is most likely illegal, "civilian arms factories" are likely not a thing in war and neither are civilian combatants. Combatants have to be identifiable as such, otherwise that's a war crime in it's own rights as it endangers civilians.
    – haxor789
    Commented May 10 at 9:29
  • Civilian combattants are illegal but they happen in most wars; as you correctly wrote they're valid targets. Arms factories are operated by civilians in almost every conventional war, they're military targets nonetheless ('civilian arms factories' was confusing). The command post in or near the hospital is sadly a classic example, as are civilians around a fuel transfer (Afghanistan). As for strategic targets, bridges and refineries are less controversial, but even the Russian attitude in UKR could be justifiable in a lot of cases in this regard.
    – Yves
    Commented May 11 at 0:40
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    The rule of distinction is not about being able to hit a military base without collateral damage to the villages around. It's about ability to actually hit specifically a military base rather than something random in a wide area. Collateral damage is controlled by rule of proportionality and it would be likely legal to hit important military base with a nuke even if adjacent villages are scorched in process. Commented May 12 at 7:22

Nuclear weapons are not specifically prohibited by international law. However, the laws of war contain quite a few general rules which are hard to reconcile with the use of nuclear weapons. Specifically:


Protocol Additional to the Geneva Convention, Article 51(2)

The civilian population as such, as well as individual civilians, shall not be the object of attack.


Article 51 also forbids:

an attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated

Superfluous Injury or Unnecessary Suffering

Article 35(2):

It is prohibited to employ weapons, projectiles and material and methods of warfare of a nature to cause superfluous injury or unnecessary suffering.

While humans close enough to ground zero is killed instantly (and therefore without suffering), humans further out may suffer 3rd degree burns, and those even further out may be afflicted with cancer.

Damage to natural environment

Article 35(3):

It is prohibited to employ methods or means of warfare which are intended, or may be expected, to cause widespread, long-term and severe damage to the natural environment.

Radioactive fallout is widespread, long-term, and likely severe. Possible exceptions include strikes in deserts or the high seas.


Targeting civilians is definitely a war crime.

Targeting a military installation is very likely a war crime.

But none of that is likely to matter to Russia, since Russia has shown little respect for international law, having recently committed not just the crime of agression, but also numerous war crimes.

What might matter, though, are the political reactions the first use of nuclear weapons outside of a world war might cause. In particular, a nuclear escalation would pose a clear risk to all other nations on earth, some of which have so far remained neutral in this conflict. Can Russia afford to recklessly endanger China and India? How will Russia finance its war, if it alienates its last remaining major trade partners?

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    The smallest tactical nuclear bombs, with a 20 kiloton yield, are about twice as powerful as the biggest conventional "bunker buster" bombs, although they are only the size of a typical mortar or tank shell. So, the considerations mentioned aren't really applicable to isolated uses of tactical nuclear weapons against military targets. See en.wikipedia.org/wiki/Davy_Crockett_(nuclear_device)
    – ohwilleke
    Commented May 10 at 18:47
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    20 kiloton is more than the nuclear weapon used on Hiroshima ...
    – meriton
    Commented May 10 at 19:20
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    I made an error in describing the units in my comment. The smallest tactical nuclear weapons are 20 tons, not 20 kilotons, of yield. I was thinking 20000 kilograms which is 20 metric tons, but that got mangled into 20 kilotons (i.e. 20,000,000 kilograms).
    – ohwilleke
    Commented May 10 at 19:32
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    "Tactical nuclear weapon" is a very broad category. According to Wikipedia, yield ranges "from a fraction of a kiloton to approximately 50 kilotons". So when Putin orders an exercise of "non-strategic nuclear weapons", he is being quite vague. It would have been easy to specify a particular warhead, or a size range. He didn't. And therefore he aims to create the impression that the entire tactical arsenal will be exercised.
    – meriton
    Commented May 10 at 20:08
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    More specifically: "On 25 March 2023, President Putin announced the stationing of tactical nuclear weapons in Belarus. Russia would maintain control of the weapons. As of May 2023 the weapons are a small number of Iskander missile warheads." The yield of an Iskander with a nuclear warhead is estimated between 5 to 50 kilotons, i.e. between 0.3 to 3 times the yield of Hiroshima.
    – meriton
    Commented May 10 at 20:28

Striking obviously civilian target is a war crime while striking clearly military target may not be.

Using nuclear weapons, however, is a separate issue, even is they are used against the valid military target. We do not want the civilization to be destroyed, even by the rules.

"Valid military target" also does not mean "it's Okay and all rightfully done" in a broader context outside the combat. If the aggressor strikes the tank of the country being invaded (while this tank is attempting to dodge the invasion by firing at the aggressor), the aggressor likely strikes the military target. This does say nothing about how much the aggressor is right with the invasion itself.


Most definitely. One is a military operation, the other is first against geneva conventions and more aligned with genocide.

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